1. Field of the Invention
The present invention relates to a colorant compound and an ink including the colorant compound.
2. Description of the Related Art
Water-soluble dyes are generally used as colorants in ink jet recording liquids (inks), but a problem associated with recorded images formed by inks including water-soluble dyes is that the images have poor storage stability. Thus, problems are associated with discoloration of images caused by solar light or various types of illumination light (light fastness) or discoloration of images caused by oxidizing gases (ozone, NOx, SOx) contained in very small amounts in the atmosphere (gas resistance).
A pyridone azo colorant compound has been suggested as a water-soluble dye for ink jet recording with the object of resolving the above-described problems (JP-W No. 2003-510398).
A colorant compound having an azo group in a 3 position of a pyrazolopyrimidine site has also been suggested as a colorant compound having a hue similar to that of the pyridone azo colorant compound (JP-A No. 06-287459).
A method for manufacturing a 6-phenyl azopyrazolo derivative as a pyrazolopyrimidine colorant compound having an azo group in a 6 position (see JP-B No. 38-13641) and xanthine oxidase inhibitor (U.S. Pat. No. 3,907,799) have also been disclosed, but not with the object of resolving the above-described problems.
A pyrazolopyrimidine colorant compound that is used as a thermosensitive transfer recording material has also been disclosed (JP-A No. 11-78258).